Bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; carbon and carbon manganese steel (Table 13)
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Si
Mn
P
S
0.15-0.23
0.10-0.40
1.30-1.70
<=0.05
<=0.05
More data from BS 970 (Part 3):1991
From the standard
Other composition limits
Steel group
Carbon and carbon manganese steel (Table 13)
Condition of supply
Bright bars: cold drawn, turned or precision ground, in straight lengths
Maximum unless a range is stated.
Source: BS 970 (Part 3):1991, Table 13
Mechanical properties by heat treatment condition
Condition
Reference symbol
Size (mm)
Tensile strength Rm (MPa)
Yield Re, min (MPa)
Elongation, min (%)
Impact Izod, min (J)
Impact KCV, min (J)
Rp0.2, min (MPa)
Hardness HB
Notes
Normalized + turned or ground
≥ 6 ≤ 150
550 min.
325
18
40
35
—
152-207
Normalized + turned or ground
> 150 ≤ 250
510 min.
295
17
—
—
—
146-197
Hardened and tempered + turned or ground
P
> 13 ≤ 150
550-700
340
18
54
50
325
152-207
Hardened and tempered + turned or ground
Q
≥ 6 ≤ 63
625-775
430
16
54
50
415
179-229
Hardened and tempered + turned or ground
R
≥ 6 ≤ 29
700-850
510
16
40
35
495
201-255
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground
P
> 19 ≤ 150
550-700
360
13
54
—
345
152-207
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground
Q
≥ 6 ≤ 63
625-775
450
12
54
—
435
179-229
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground
R
≥ 6 ≤ 29
700-850
520
12
40
—
510
201-255
Condition letters P to Z are the tensile strength ranges of Table 29. Rp0.2 applies when specifically ordered (note 3). Hardness HB is for guidance only except in the softened condition (note 13). Impact: Izod, or KCV when the standard impact test is not required (option A.3).
Source: BS 970 (Part 3):1991, Table 20
Heat treatment temperatures
Normalizing temperature
860-900 deg C
Hardening temperature
860-900 deg C, oil or water
Tempering temperature
550-660 deg C
Normalizing, hardening and tempering temperatures as given in Tables 27 and 28 (clause 4.2); Table 22 hardening temperatures for case hardening steels.
Source: BS 970 (Part 3):1991, Table 27 and Table 28
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